Eight core sector industries' growth has slowed down to 2.9% in March 2013 from 3% in the same month in 2012 due to drop in production of coal and crude oil.
"The marginal decline in growth in March was on account of negative growth witnessed in the production of natural gas and low growth recorded in the production of coal and crude oil," an official release said on Tuesday.
During 2012-13, expansion of the eight industries - crude oil, natural gas, cement, coal, electricity, steel, petroleum refinery products and fertilisers - was down at 2.6% against 5% in 2011-12.
The eight industries have a weightage of 37.9% in the overall Index of Industrial Production (IIP).
Production of natural gas contracted by 17.7% in the month under review. Coal and crude oil output growth dropped to 0.3% and 0.2% respectively, against 7.3% and (-) 2.9% respectively in March 2012.
Cement production growth slowed to 6.6% in the reported period against 7.1% in March 2012.
However, petroleum refinery and fertiliser production grew by 5.6% and 3.6% in March 2013 against 1.6% and 1.5%, respectively, in the year-ago period.
Steel output increased by 6.6% from 6.2% in March 2012. Electricity generation grew by 3% from 2.8%.
The growth of eight core sector industries had contracted by 2.5% in February, the first time in 2012-13.